Introducers, or introducer sheaths, are used for minimally invasive placement of medical devices, such as catheters, into the vasculature. Introducers typically include a tube that is inserted percutaneously into a vascular structure and a valve, including a sealing member, positioned at a proximal end of the tube. The valve, which is positioned outside the body of the patient, may be a hemostasis valve for reducing blood loss at the valve. Delivery catheters are used for a variety of diagnostic and/or therapeutic purposes and may be introduced into the vascular structure through the hemostatic valve of the introducer. The introducer thus provides access for a delivery catheter, or other similar medical device, and protects walls of the vascular structure from damage during insertion of the delivery catheter.
According to some percutaneous vascular procedures, the delivery catheter may require repositioning, including insertion and withdrawal, relative to the introducer. For example, during a medical device placement procedure, a portion of the delivery catheter may require retraction relative to the introducer, to deploy the medical device. During this proximal retraction, or withdrawal, it may be necessary to maintain a stationary position of both another portion of the delivery catheter and the introducer, particularly in light of the friction between the sealing member of the valve and the delivery catheter. This maneuvering can be difficult, particularly since precise positioning and movement of the respective components is important for proper medical device placement.
U.S. Pat. No. 8,114,057 to Gerdts et al. (hereinafter “Gerdts”) discloses a stent delivery system including an adaptor having a valve, a coaxial catheter assembly configured to extend through the valve, and a telescoping sleeve including a plurality of telescoping tubes. The first tube of the plurality of telescoping tubes may be secured to the adapter using the valve and, when the coaxial catheter assembly is positioned through the adaptor, the first tube may be positioned between the catheter assembly and the adaptor. The telescoping sleeve may be proximally extended to abut a distal portion of a handle of the catheter assembly. As such, the portion of the catheter assembly between the adaptor and the handle may be inhibited from bowing or arching outward using the extended telescoping sleeves. In addition, the friction between the tubes of the telescoping sleeve may help inhibit the handle from moving distally relative to the adaptor during stent deployment using the coaxial catheter. Although the system of Gerdts may be useful for some applications, it should be appreciated that there is a continuing need for efficient and effective catheter systems.
The present disclosure is directed toward one or more of the problems or issues set forth above.